Chlorinating ethylene hydrocarbons



Nov. 26, 19 35 M. BERLJNER CHLORINATING ETHYLENE HYDROCARBONS Filed May18, 1934 INK EkM

Jig/er Ber/her INVENTOR 4);,- ATTORNEY Patented Nov. 26, 1935 cgETHYLENE HYDRO- ABBONS Meyer Berliner, Edgemere, N. Y., assignor to TheTexas Company, New York, N. Y., a corporation of Delaware ApplicationMay'1 8, 1934, Serial No. 726,256

7 Claims. (01. 260-162) This invention relates to the 'halogenation ofhydrocarbons of the ethylene series and more particularly to a processof chlorinating ethylene hydrocarbons whereby the dichlor derivatives of5 the hydrocarbons are produced.

My invention contemplates a method of chlorinating hydrocarbons of theethylene series wherein hydrocarbons such as ethylene, propylene,butylene, and the like, are reacted with chlorine in the presence ofhigh boiling chlorinated compounds such as the trichlor and tetrachlorderivatives of propane and butane, or mixtures of these compounds,whereby high yields of the dichlor derivatives of the ethylenehydrocarbons are obtained. The reaction mixture may then be freed fromdissolved chlorine and the hydrochloric acid by a suitable procedure,after which the reaction mixture is subjected to a distillation step. Bymeans of the distillation operation, the desired 20 dichlor derivativesare segregated as a separate fraction while the high boiling chlorderivatives are separated and recycled to the chlorination reaction.

The preparation of dichlor derivatives of ethyl-- 25 ene hydrocarbonshas always presented considerable difficulty and numerous expedientshave been proposed to overcome this. The most success apparently hasbeen had by employing solvents which dissolve both the chlorine and the30 hydrocarbons. In this connection, cognizance is had of U. S. PatentNo. 1,231,123 issued to Benjamin T. Brooks and Dillon F. Smith. Thispatent discloses the preparation of dichlor derivatives of ethylenehydrocarbons by reacting these hydro- 3 carbons with chlorine in thepresence of a mutual solvent. As mutual solvents the inventors proposechloroform, carbon tetrachloride, carbon disulfide tetrachlorethane, anddichlorinated ethylene hydrocarbons.

40 I have discovered that by employing the trichlor and tetrachlorderivatives of propane and butane, higher yields of the dichlorderivatives of the ethylene hydrocarbons can be obtained than arepossible when using the mutual solvents dis- 45 closed by Brooks andSmith.

In the practice of my invention, I may employ basis of my invention ismost effectively carried out by maintaining a body of one of the above'solvents or any mixture of these, and passing thereintc chlorine andthe ethylene hydrocarbons to be chlorinated. When conducted in this way,6 the reaction is quite rapid and smooth, and a high percentage of thedichlor derivatives is formed. Although the reaction is advantageouslycarried out at a low temperature such as of the order of 0., lower orhigher temperatures may be used, 1 the choice of the proper temperaturebeing de pendent upon the type or types of ethylene hydrocarbonsundergoing reaction. The reaction is advantageously carried out under apressure in the neighborhood of atmospheric. However, in certainapplications of the invention, it may be desirable to use higherpressures which may be as high as 200 pounds per square inch or higher.

The above described invention has been incorporated in a chlorinationprocedure which will 29 be readily understood by reference to theaccompanying drawing which shows in diagrammatic sectional elevation asuitable apparatus for emciently carrying out the process.

In the figure, the numeral til refers to a storage for the solvent. Thisvessel is connected through the line H and the valve it with the inletside of the pump 03. This pump is connected by the line I4 controlled bythe automatic float-controlled valve l5 with the spray it which issupported in an upper portion of the reaction vessel l'l.

The numeral 2t refers to a storage tank r'cr ethylene hydrocarbons whichis connected through'the line 2! and the valves 22 and 25% with theinlet side of the pump M. This pump is connected by the line 2%controlled by the valve 29 with the spray 30 which is situated atalow'erpoint in the reaction chamber ii. A bypass line 25 controlled bythe valve 26 connects line 2! at a point intermediate the valves it and23 with the line 28.

pressure used in the process and also constructed of such material as isproof against the corrosive toy-products that are formed in the courseof the reaction. The vessel is provided with cooling coils 32 formaintaining the reaction mixture at the proper temperature and withinsulation it. to prevent absorption of heat from the surroundingatmosphere. The vessel is also provided at a point below the spray ISwith a bed 33 of distributing material such as Raschig rings, tile,pumice stone, or the like, supported on a foram- 5 e This iced acts bothas a distribr the solvent which is injected and also serves to minimisethe cuts by the formation of mists. The top oi 61 e vessel is providedwith a vapor drawofl line 3? controlled by the valve 31 which connectsthe vessel with a storage provision or an apparatus ior recovering anyunreacted ethylene hydrocarbons. There is inserted into a lower point ofthe vessel spray it whidh is connected through the valve with a sourceor supply of chlorine. There provided at a point immediately above thespray a bed to of distributing material such as Raschig rings, tile,pumice, or the like which is supported on a ioraminous plate ti.

' This bed which may be of varying depth serves to facilitate theinteraction of the reactants.

The lowermost point of the reaction vessel ill is connected by the line53 controlled by the valve M with the pump lii which discharges throughthe line to and the valve ll into the top of the washer to. The washercomprises essentially a vessel provided with a mechanical agitatingdevice 49. It is connected through the line to controlled by the valvevwith the discharge side of the pump 52. The inlet side of this pump isin turn connected through the line 53 and the valve 54 with the storagetank 55 for wash liquid. The bottom of the washer is provided with adischarge line 56 controlled by the valve 57 which connects it with thesettling chamber 58. This chamber is provided at its uppermost pointwith a discharge line 59 controlled by the valve 60 which leads to asump, while the bottom of the vessel discharges through the line BI andthe automatic float-controlled valve 62 into the intake side of the pump63. The discharge side of this pump is connected through the line 64 andthe valve 55 with the drying chamber 86. This drying chamber is a vesselcontaining drying chemlcals such as anhydrous calcium chloride,anhydrous copper sulfate or any other material which readily absorbswater and which does not detrimentally affect the products of thechlorination. The drier is connected by the line 61 controlled by thevalve 68 with the. heating coil 69 situated in the heater l0.

In order to permit of the by-passing of the washing and dryingapparatus, there is provided the by-pass line 12 controlled by the valve13 which connects the line 46 at a. point intermediate the pump 45 andthe valve 41 with the line 61 intermediate the valve 68 and the inlet tothe heating coil 69.

The heater consists essentially of theheating coil 69 and 9. containingvessel through which a heating medium such as high pressure hot oil orthe like may be circulated. The outlet of the heating coil 89isconnected through the line and the expansion valve 16 with a lowerpoint of the fractio'nating tower 11. This tower is advantageouslyprovided at an upper point of its structure :ith a cooling coil I8 whichserves to provide reflux for the tractionating operation. The top of thetower is connected through the line I9 controlled by the valve 80 withthe coil 8| of the condenser 82. The outlet side of this condenserdischarges through the line 83 controlled by the valve 84 to a suitablestorage. The bottom of the Iractionating tower is connected by the line8i controlled by the valve 81 through the pump 88 with the storage tankIII.

In a typical operation of the present process, an ethylene hydrocarbonor a mixture of ethylene hydrocarbons is drawn from the storage tankassassin and delivered under its own pressure or bypurnp pressure to theline '28 and thence to the spray situated within the reaction chamberiii. There is simultaneously delivered into the upper portion of thereaction chamber through 5 the spray it a quantity of one of thepreviously described solvents which may consist either of a. trichlor ortetracblor derivative of propane or butane or any mixture of thesederivatives. The

quantity of solvent supplied is automatically con- 10 trolled by meansof the float-controlled valve l5. There is also injected into thereaction vessel through the spray it a: measured and controlled quantityof chlorine.

The chlorine and ethylene hydrocarbon or by- 15 drocarbons are mutuallydissolved by the solvent and a rapid reaction resulting in the formationof the dichlor derivatives of the ethylene hydrocarbon or hydrocarbonsoccurs.

The temperature maintained with the reaction chamber l'l' must be keptwithin closely controlled limits in order to effect the highest possibleconversion of the ethylene hydrocarbons into dichlor derivatives.Although no specific temperature can be given since the same isdependent on the pressures used in carrying out the reaction, as well ason the types of ethylene hydrocarbons undergoing chlorination, in mostcases temperatures below 60 F. may be employed with advantage.

The products of the reaction become dissolved in thesolvent and thissolution is continuously withdrawn from the bottom of the reactionchambe:- through the line 43 and delivered to the pump 45 which deliversthe same either directly to the heater 10 or else through the washingand drying apparatus. In the latter case, the solution of dichlorderivatives in solvent is delivered under a suitable pressure into thewashing chamber 48 wherein the solution is washed with water or anaqueous alkaline solution in order to free it from free chlorine orhydrochloric acid. This is accomplished by thoroughly agitating thesolvent solution of dichlor derivatives with the wash liquid and thendelivering the mixture to the separatory chamber 58 wherein the dichlorderiva-- tives in solvent are caused to separate from the spent washliquid. The latter is drawn on and passed to a sump while the former arecharged by means of the pump 63 through the drying chamber wherein anyremaining water is removed by the hygroscopic drying materialscontainedtherein. The dried solution of dichlor derivatives in solvent is thendelivered to the coil 6! of the heater 10 wherein it is heated to anelevated temperature above the vaporization temperature of the dichlorderivatives. The heated solution is then passed through the expansionvalve IO into a. lower point of the fractionating tower 11 where thedichlor derivatives are separated from the solvent liquid. The formerare vaporized and are delivered from the top of the tower to thecondenser 82 where they are condensed. The solvent liquid, on the otherhand, collect: as a pool at the bottom of the fractionatlng tower I1from which it is drawn through the line 80 by means or the pump 88 andreturned to the solvent storage tank l0.

Comparative experiments have been conducted on the preparation ofdichlor derivatives of mixed ethylene hydrocarbons and comprisingparticularly ethylene, propylene and butylene. These hydrocarbons werereacted with chlorine inthe presence of dlflerent solvents. The solvent:em- 7 ployed were:

ace-2,016

1. The dichlorides of the hydrocarbons formed by the chlorination of thehydrocarbons used in the experiments.

2. Symmetrical tetrachlorethane.

3. A mixture of trichlor and tetrachlor propanes and butanes having aboiling range of approximately 130" to 205 C.

The procedure that was followed consisted in maintaining a body of theparticular Solvents at a temperature of 41 F. and introducing thereintochlorine and the mixed ethylene hydrocarbons. The controlling primevariables were maintained substantially uniform and constant. Theseincluded the temperatures, pressures and quantity of reagents deliveredto the reaction zone in a unit of time. The solvents containing thedichlor derivatives were then subjected to a distillation operation andthe dichlor derivatives separated as distinct fractions. The yieldsobtained with the solvents set forth above were as follows:

me in percent of theoretical Solvent Olefin Chlorine basis basis l.Dicblorldes of mixed ethylene hydrocarbOIB 54.1 64.8 2. Symmetricaltetrachlorethano 54.9 64. l

3. Mixed trichlor and tetrachior propanes and bntanes 68. 6 76. 8

These results indicate that the solvents which I' have discovered permitof increased yields of ethylene hydrocarbon dichlorides over thesolvents proposed in the past.

Although I have described this invention in connection with thepreparation of dichlor derivatives of ethylene hydrocarbons present inhigh concentrations, the reaction may nevertheless be advantageouslyused in dichlorinating ethylene' of the invention, as hereinbefore setforth, may 1 be made without departing from the spirit and "scopethereof, and therefore only such limitations 1. A method of preparingdichlor derivatives of ethylene hydrocarbons which comprises reacting 5the ethylene hydrocarbons with chlorine in the,

presence oi amixture of trichlor and tetrachlor propanes and trichlorand tetrachlor butanes.

2. The method of preparing dichlor derivatives of ethylene hydrocarbonswhich comprises main- 1 'taining a body of a mixture oi trichlor andtetrachlor propanes and trichlor and tetrachlor'butones, and passingthereinto astream of chlorine and a-stream oi the ethylene hydrocarbons.

3. The method of preparing dichlor derivatives 15 of ethylenehydrocarbons which comprises reacting the ethylene hydrocarbons withchlorine in the presence of a mixture of trichlor and tetrachlorpropanes and trichlor and tetrachlor butanes at a temperature of in theneighborhoodoi 5 C. 20

4. The method of preparing dichlor derivatives of ethylene hydrocarbonswhich comprises reacting the ethylene hydrocarbons with chlorine in thepresence of a mixture of trichlor and tetrachlor propanes and trichlorand tetrachlor bu- 25 tanes and under superatmospheric pressure.

5. The method of preparing the dichlor derivatives of ethylenehydrocarbons which comprisesreacting the ethylene hydrocarbons withchlorine in the presence of a solvent consisting of trichlor 30 andtetrachlor propanes and trichlor and tetrachlor butanes whereby theso-iormed dichlor derivatives become dissolved in the solvent togetherwith unreacted chlorine and hydrochloric acid, washing the reactionproduct to remove the chlo- 35 rine and hydrochloric acid and finallyseparating the dichlor derivatives. from the solvent by distillation,and'returnlng the solvent to thereaction.

6. A- method of preparing dichlor derivatives of ethylene hydrocarbonswhich comprises react- 4'0 ing the ethylene hydrocarbons with chlorinein the presence of a solvent selected from the group consisting oftrichlorpropane, trichlorbutane, tetrachlorpropane, andtetrachlorbutane.

7. A method 01 preparing dichlor derivatives of 45 solvents selectedfrom the group consisting of triclorpropane, trichlorbutane,tetrachlorpropane,

and tetrachlorbutane.

MEYER IBERIINER.

